Deliverability
Blacklist Checker
Checks an IPv4 address or a domain against free public blocklists and gives delisting links for any hit.
- Runs on our server
- 2 units per run
- You enter
- An IPv4 address, a domain or a URL.
- You get
- Listed or clean for each list, with the lists' answers and delisting links.
- A good result
- "No public listings found" across all seven lists.
On this page
#What it is for
Use it when bounces mention a blocklist, when a sending IP suddenly loses deliverability, or before you trust a link domain. It is a quick public check, not continuous monitoring.
#What you enter
One field: an IPv4 address (192.0.2.10), a domain (mail.example.com) or a whole URL (the host is taken from it).
#How it works
Seven free lists are asked over DNS:
- IP lists: Spamcop, SORBS, blocklist.de, Manitu.
- Domain lists: Spamhaus DBL, SORBS RHSBL, SURBL.
An IP is checked against the IP lists. A domain is checked against the domain lists, and then up to 5 of its IPv4 addresses are checked against the IP lists.
#Reading the results
The verdict is "No public listings found" or "Public blacklist hits found", with totals for direct IP hits, domain hits and hits on resolved addresses. Each list shows Listed or Clean, the query and how long the answer took.
When something is listed, delisting links for those lists appear at the top. Fix the cause first (a compromised form, a bad list import), then request removal.
#Example
mail.example.comThe domain is checked on the three domain lists, then its addresses on the four IP lists.
#Limits and gotchas
- Coverage is best effort: a clean result does not prove a good reputation, and paid lists are not included.
- IPv6 is accepted but not checked; the tool warns about limited coverage.
- Each list gets 4 seconds. A slow list can time out and show as clean.